1. Field
The present application relates generally to the operation and design of amplifiers, and more particularly, to amplifiers with improved noise reduction.
2. Background
There is an increasing demand to provide high quality audio and video from a variety of user devices. For example, handheld devices are now capable of rendering high definition video and outputting high quality multichannel audio. Such devices typically require audio amplifiers that are designed to provide high quality signal amplification.
Click and pop noise (CnP) during startup and/or shutdown is a common problem in audio amplifiers. Various factors contribute to generating this type of noise, for example, glitches produced during power-up and power-down, amplifier offset voltages, and glitches or voltage offsets associated with the signal source. Extremely low levels of click and pop noise (i.e., less than 100 micro volts) may be needed especially for headphone amplifiers.
Therefore, it is desirable to have an amplifier with improved noise reduction.